TERRE HAUTE, Ind. (WTHI) – Most of us “probably” think of a warm July night when it comes to spotting fireflies.

You might not know that you can see them another form right now, known informally as “glow worms” or firefly larvae. It’s a sight that Rose Hulman Biologist Dr. Peter Coppinger looks forward to every October.

“It’s always sad in the summer when the fireflies start to disappear, but if you just wait a couple of months, you’ll see them again, in this form,” said Coppinger.

The firefly spends most of its one to two year lifespan as a glowing larvae. It’s only in the last couple weeks of life that they grow wings and go looking for a mate. When they glow in the larval stage, it serves as a warning.
“They tend to glow as a warning to predators,” explained Coppinger. “These are often distasteful and sometimes poisonous to things that would eat them. You may even notice if you pick them up and hold them, they’ll start to glow steadily or start to pulsate their light as a warning to you.”

Firefly populations often stay in the same relative location for many generations. This means that if you can remember where you saw the “flies” (they’re actually beetles), you might run into some of the glow worms.The larvae typically hibernate starting in November and then emerge again in April.

So look for these little glowing guys if you happen to be out on a quiet fall evening. Shortly after sundown seems to be the best time to find them.